Abstract
To evaluate the performance of computed high b value diffusion-weighted images (DWI) in prostate cancer detection. 97 consecutive patients who had undergone multiparametric MRI of the prostate followed by biopsy were reviewed. Five radiologists independently scored 138 lesions on native high b-value images (b = 1200 s/mm2), apparent diffusion coefficient (ADC) maps, and computed high b-value images (contrast equivalent to b = 2000 s/mm2) to compare their diagnostic accuracy. Receiver operating characteristic (ROC) analysis and McNemar’s test were performed to assess the relative performance of computed high b value DWI, native high b-value DWI and ADC maps. No significant difference existed in the area under the curve (AUC) for ROCs comparing B1200 (b = 1200 s/mm2) to computed B2000 (c-B2000) in 5 readers. In 4 of 5 readers c-B2000 had significantly increased sensitivity and/or decreased specificity compared to B1200 (McNemar’s p < 0.05), at selected thresholds of interpretation. ADC maps were less accurate than B1200 or c-B2000 for 2 of 5 readers (P < 0.05). This study detected no consistent improvement in overall diagnostic accuracy using c-B2000, compared with B1200 images. Readers detected more cancer with c-B2000 images (increased sensitivity) but also more false positive findings (decreased specificity).
Highlights
Prostate cancer is the most common solid organ malignancy in American men, accounting for an estimated 220,800 new cases and 27,540 deaths in 20151
No significant difference existed between the B1200 and computed B2000 (c-B2000) area under the curve (AUC) for any of the 5 readers, as indicated by the complete overlap of corresponding AUC values for the B1200 images with the 95% confidence intervals for the c-B2000 images, and vice-versa, for every reader
While no differences were identified in diagnostic accuracy between B1200 and c-B2000, differences were seen between high b-value diffusion weighted imaging (DWI) and apparent diffusion coefficient (ADC) for some readers
Summary
Prostate cancer is the most common solid organ malignancy in American men, accounting for an estimated 220,800 new cases and 27,540 deaths in 20151. Pre-biopsy MRI enables image-targeted biopsy via direct MRI-guidance5or MRI-transrectal ultrasound (TRUS) fusion-guided biopsy[6,7,8] These methods both improve diagnosis of clinically significant prostate cancer when compared to conventional biopsy methods. DWI is a functional imaging technique that probes tissue structures at the cellular level It is one of the important components of the Prostate Imaging and Reporting Archiving Data System (PI-RADS). Normal glandular prostate tissue on MRI gives no signal reduction on the ADC map and no increase in signal intensity on the high b-value images (PI-RADS 1). Despite its role as the most important component of mpMRI, DWI is limited by artifacts from physiologic motion, susceptibility, and chemical shift These are compounded by inherent limitations in signal-to-noise ratio and image resolution. Improving DWI performance is an important goal that would improve the clinical utility of mpMRI
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
